Process of dyeing.



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Specification of LetteriPatent. f

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No Drawing. Original application filed December 26, 1914, Serial-No. 879,210. Danced and this application filed August 12,1,915. Serial No; 45,196.

To all whom itymag concern:

Be it known that we, EDWARD Loner: and James Moneax EVANS, both subjects of the King of Great Britain, and residing at Huddersfield, in the county of York, Eng

land, have invented a new and useful Im provement 1n Processes of Dyeing, of which the following is a specification.

Our invention relates to the application of sulfur dye-stuffs for dyeing animal textile fibers andfabrics (wool, hair, feathers, furs and silks) also artificial silks, and

union goods composed of a mixture of animal and vegetable fibers and artificial silks 0. animal fibers, mixed With cotton, flax,

jute, rhea, ramie, china'grass or hemp).

'The usual method of applying sulfur colors to vegetable fibers and fabrics is to reduce and dissolve the color with the aid of sodium sulfid. This method is however not applicable for dyeing animal fibers or fabrics containing animal fibers, owing to the strong alkalinity of the bath dyeliquors.

The applicants have found that, if the sulfur colors be reduced to their leuco compounds by means of a hydrosulfite of an alkali-metal, e. g. Na S O or K S O in presence of a normal sulfite of an alkalimetal, 6. g. Na SO or K 89 and any alkali (often present in the color) removed or exchanged for the weaker alkali, am-

monia, animal fibers can thereby be dyed without injury. a The action of the normal sultite of anaflkalirmetal appears to be at least twofold. It converts any free sulfur present in the color into thiosulfates and changes any polysulfids into thiosulfates and normal sulfids and secondly it dissolves (renders soluble) the coloring matter itself. x

The dye-bath is 'most conveniently prepared by first boiling together the color and sulfite' of sodium or potassium and water, then adding the hydrosulfite and stirring carefully until reduction and'solution are complete. This concentrated solution of the prepared dye isadded to the dye-bath containing the requisite quantity.v of Water which has previously been heated to the required temperature.

The following example may be given "of the preparation is added to are sulfid of .monia. Suitable ammonium salts are the chlorid, normal sulfate and. acetate.

The alkalis soda and caustic soda. The reactions whereby they are exchanged for the weaker alkali or are removed are as follows As an example, wool will be worked in the dye solution at 70-80 C. For unions of cotton and wool the cotton may be dyed at a temperature up to about 40 (1, raising the temperature up to "7080, the wool is then, dyed. Or the order may be reversed. The additioni of Glauber salt or common salt assists, as

haustion of the dye liquor.

Vhat we claim is 1. A method or process of dyeing animal fibers (including furs and feathers) union goods and artificial silk in any stage of manufacture, according to which sulfur colors are reduced by a hydrosulfite of an alkali-metal in the. presence ofga sulfite of an alkall-metah v y p 2. A method or process of dye ng animal fibers (including furs and'feathers) union goods andartificial silk in any stage ofmanufacture, according to wvhich sulfur colors are reduced by a hydrosulfite of an alkali metal in the presence of a sulfite of an alkali-metal, and a neutral jammomum salt. V

EDVARD LODGE." JAMES MORGAN EVANS. "Witnesses:

WM. RAMsDEN, ARNOLD MELLOR.

of a typical dye-bath from exchange caustic alkali for amoften present in .sulfid colors- 8.0 l is well known, eX- 

